Multidisciplinary Observing in the World Ocean’s Oxygen Minimum Zone Regions: From Climate to Fish — The VOICE Initiative
"Multidisciplinary ocean observing activities provide critical ocean information to satisfy ever-changing socioeconomic needs and require coordinated implementation. The upper oxycline (transition between high and low oxygen waters) is fundamentally important for the ecosystem structure and can be a useful proxy for multiple observing objectives connected to eastern boundary systems (EBSs) that neighbor oxygen minimum zones (OMZs). [...]"
Source: Frontiers in Marine Science
Authors: Véronique Garçon et al.
Dark carbon fixation in the Arabian Sea oxygen minimum zone contributes to sedimentary organic carbon (SOM)
"In response to rising CO2 concentrations and increasing global sea surface temperatures, oxygen minimum zones (OMZ), or “dead zones”, are expected to expand. OMZs are fueled by high primary productivity, resulting in enhanced biological oxygen demand at depth, subsequent oxygen depletion, and attenuation of remineralization. This results in the deposition of organic carbon‐rich sediments. Carbon drawdown is estimated by biogeochemical models; however, a major process is ignored: carbon fixation in the mid‐ and lower water column. [...]"
Source: Global Biogeochemical Cycles
Authors: Sabine K. Lengger et al.
‘Dead zones’ expanding rapidly in oceans as climate emergency causes unprecedented oxygen loss
The overall level of oxygen in the oceans has dropped by roughly 2 per cent, while the number of known hypoxic “dead zones” – where oxygen levels are dangerously low – has skyrocketed from 45 known sites in the 1960s to at least 700 areas now dangerously devoid of the life-giving compound, some encompassing thousands of square miles. [...]"
Source: The Independent
World’s Oceans Are Losing Oxygen Rapidly, Study Finds
"The world’s oceans are gasping for breath, a report issued Saturday at the annual global climate talks in Madrid has concluded.
The report represents the combined efforts of 67 scientists from 17 countries and was released by the International Union for Conservation of Nature. It found that oxygen levels in the world’s oceans declined by roughly 2 percent between 1960 and 2010. The decline, called deoxygenation, is largely attributed to climate change, although other human activities are contributing to the problem. One example is so-called nutrient runoff, when too many nutrients from fertilizers used on farms and lawns wash into waterways. [...]"
Source: The New York Times
EGU General Assembly 2020
Aims & scope
The EGU General Assembly 2020 will bring together geoscientists from all over the world to one meeting covering all disciplines of the Earth, planetary and space sciences. The EGU aims to provide a forum where scientists, especially early career researchers, can present their work and discuss their ideas with experts in all fields of geoscience. The EGU is looking forward to cordially welcoming you in Vienna.
Abstract submission (deadline: 15 January 2020, 13:00 CET)
For further information please visit the event's homepage.
Start Date: 5/3/20
Ocean deoxygenation : everyone’s problem
"The ocean represents 97% of the physical habitable space on the planet and is central to sustaining all life on Earth. Since 2000 significant and dedicated effort has been directed at raising awareness and understanding of the consequences of greenhouse gas emissions on the ocean. Carbon dioxide emitted by human activities is driving the ocean towards more acidic conditions. Only in the past decade has it started to become more widely recognized that the temperature of the global ocean is also being significantly affected as a result of the effect that the carbon dioxide and other potent greenhouse gases are having in the Earth’s atmosphere. [...]"
Authors: D. Laffoley and J. M. Baxter
Diel and tidal pCO2 × O2 fluctuations provide physiological refuge to early life stages of a coastal forage fish
"Coastal ecosystems experience substantial natural fluctuations in pCO2 and dissolved oxygen (DO) conditions on diel, tidal, seasonal and interannual timescales. Rising carbon dioxide emissions and anthropogenic nutrient input are expected to increase these pCO2 and DO cycles in severity and duration of acidification and hypoxia. [...]"
Source: Scientific Reports
Authors: Emma L. Cross et al.
Spatiotemporal redox heterogeneity and transient marine shelf oxygenation in the Mesoproterozoic ocean
"The Mesoproterozoic Era (1.6-1.0 Ga), long regarded as an interval of sluggish biotic evolution and persistently low atmospheric-oceanic oxygen levels, has become the subject of recent controversy regarding putative large-scale oxygenation events. In this study, we conducted a comprehensive investigation of redox, productivity, seawater sulfate concentrations, and hydrographic conditions for the ∼1.4-1.32-Ga Xiamaling Formation in the shallow Hougou and mid-depth Huangtugui sections in the Yanshan Basin (North China). [...]"
Source: Geochimica et Cosmochimica Acta
Authors: HaiyangWang et al.
Ocean acidification – a silently progressing crisis
"Ocean warming, acidification, deoxygenation, and marine heatwaves are all pressing marine issues that are quietly intensifying around the world. These challenges are diverse and occur on a massive scale, making it difficult for people to understand the full extent of the problem. To shed some light on this topic, the Sasakawa Peace Foundation (SPF) spoke with Mr. Tsunoda, Senior Research Fellow at the Ocean Policy Research Institute (OPRI). [...]"
Source: Sasakawa Peace Foundation
Marine animals hold promise for extending ocean monitoring
"An international team of researchers led by the University of Exeter suggests that a wide variety of marine species could be used for monitoring the world's oceans. Using electronic tags, scientists could exploit the natural behavior of sharks, penguins, turtles, seals and other species to fill gaps in our knowledge of the seas.
With three-quarters of the Earth's surface covered with water, having a comprehensive understanding of the oceans is very important in dealing with everything from fishing quotas to climate change. The problem is that the oceans are much bigger than most people realize and many parts aren't easily, if at all, accessible."
Source: New Atlas